1. Field of the Invention
With reference to the field of art as established in and by the U.S. Patent Office, the present invention is believed to be found in the class entitled, "Amusement Devices," Games (Class 273) and in the subclass entitled, "Tennis Rackets" (Subclass 73R).
2. Description of the Prior Art
Conventional tennis rackets are based on a design established over many years. The frame of these rackets is conventionally of wood, metal of graphite composition. All these frames are lightweight for ease in manipulation by the user. They are individually selected so that a sufficient weight in the head is available for the striking of the ball with a controlled or predetermined force. A heavy racket with a heavy head, of course, has a capability of propelling the struck ball at a greater rate than a lighter racket. An increase in the weight in the head of a racket makes it more difficult to control and also is more fatiguing.
Weighted heads in tennis rackets are not new and the Professionals use lead tape to give added weight to the head of the racket. Just as the Professionals and advanced amateurs vary the tension of the strings they change weights in the head for different court conditions. The present invention enables the occasional tennis buff to change the weight to suit playing conditions and to accommodate muscle tone or training. Movable weight apparatus utilizing springs is shown in prior art patents for tennis rackets but a sliding weight as in the embodiments to be described are believed to be novel and practical.
In the present invention the increased force provided by a weighted head is achieved by a sliding or shifting weight that is easily controlled by the user of the racket. When a greater weight is desired in the head and a greater force is to be applied to the ball a heavier weight is slidably mounted in the head to provide an increase in the propulsive force. The present invention proposes to retain the weight which is carried in or near the handle when the racket is used for strokes that do not require or desire a large or optimum propulsive force.
A number of prior art devices such as the racket shown in U.S. Pat. No. 3,975,018 to WALKER, issued on Aug. 8, 1975 and also baseball bats, golf clubs and the like have employed movable weights for the shifting of the center of gravity. None of these prior art devices have employed means for restraining the movement of the weight outwardly by the use of inhibiting or latching means. In this invention the weight in or near the handle is released to allow said weight to be moved outwardly toward the head to increase the head weight of the racket.